Real Time In swing to a label

Real_Time.java

public class PlaySchoolClock {

    public static void main(String[] args) {
        new PlaySchoolClock();
    }

    public PlaySchoolClock() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new ClockPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class ClockPane extends JPanel {

        private JLabel clock;

        public ClockPane() {
            setLayout(new BorderLayout());
            clock = new JLabel();
            clock.setHorizontalAlignment(JLabel.CENTER);
            clock.setFont(UIManager.getFont("Label.font").deriveFont(Font.BOLD, 48f));
            tickTock();
            add(clock);

            Timer timer = new Timer(500, new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    tickTock();
                }
            });
            timer.setRepeats(true);
            timer.setCoalesce(true);
            timer.setInitialDelay(0);
            timer.start();
        }

        public void tickTock() {
            clock.setText(DateFormat.getDateTimeInstance().format(new Date()));
        }
    }
}